Electrostatic flocking procedures and apparatus



g- 1955 s. M. SCHWARTZ ET AL 2,715,585

ELECTROSTATIC FLOCKING PROCEDURES AND APPARATUS Filed March 15 1951 4Sheets-Sheet l Dan/Z425 Gross FF W6 ATT RNEY 6, 1955 s. M. SCHWARTZ ETAL 2,715,585

ELECTROSTATIC FLOQKING PROCEDURES AND APPARATUS Filed March 15, 1951 4SheetsSheet 2 k. Q| m Q @Q 1 WQ w? N ILI A INVENTOR Samuel M. SckwamiZhznz' 0P0;

ATT RNEY g- 1955 s. M. SCHWARTZ ET AL 2,715,585

ELECTROSTATIC FLOCKING PROCEDURES AND APPARATUS Filed March 15, 1951 4Sheets-Sheet 3 Fig.5. 44215 7 v INVENTOR SamzzeZMSc'ka/afiiy 4 ORN E Y6, 1955 s. M. SCHWARTZ ET AL 2,715,585

ELECTROSTATIC FLOCKING PROCEDURES AND APPARATUS Filed March 15, 1951 4Sheets-Sheet 4 l q- 1/29 2 1/29 123 60752 a- 3 i jfi i .162

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.DanzeZ 07101515 B Y United States Patent Office ELECTROSTATIC FLOCKINGPROCEDURES AND APPARATUS Samuel M. Schwartz and Daniel Gross, Paterson,N. J., assignors to Velveray Corporation, New York, N. Y., a corporationof New York Application March 15, 1951, Serial No. 215,726 26 Claims.(Cl. 117--17) The present invention relates to flocking procedures andapparatus and it particularly relates to methods and means ofelectro-static flocking of various sheet materials.

Although not limited thereto, the present invention will be particularlydirected and described in its application to the flock printing or tofabrics and particularly woven textile fabrics although it has a muchbroader application to the flocking or flock printing of other textilefabrics as well as sheet materials such as paper and plastic films.

In flock printing or in flocking of textile fabrics with finely dividedor chopped up fibres such as rayon, nylon, cotton or other cellulosic ornitrogeneous fibres of natural or synthetic origin, it has been foundthat special controls and procedures are necessary. For example, theseshort relatively thin fibres are subject to altogether different laws inrespect to their deposition and adherence to woven textile materials,than would be the case with granular particles such as those of anabrasive nature which do not too greatly differ in length, width andthickness.

In connection with chopped up and finely divided textile fibres, it hasbeen found that in all cases no matter how line the subdivision hasbeen, the length of the fibres is always many times and tremendouslygreater than the diameter of the individual fibres and it has also beenfound that upon deposition of such fibres upon the cloth or woven fabricwhich has been previously printed or impregnated with adhesive material,it is necessary that the fibres be aligned substantially parallellybefore contact or coating with the still liquid or fluid adhesive.

In general it has been found that procedures which are applicable togranular materials are not general in application to chopped up fibrousmaterials or finely divided rayon fibres.

It is therefore among the objects of the present invention to provide aflock printing procedure or a flocking procedure and an apparatustherefor which is particularly applicable to the flock printing ordeposition of finely divided or chopped up textile fibrous materialsupon woven fabrics or other textile or sheet materials.

Another object of the present invention is to provide a novelelectro-static deposition method and means particularly applicable tothe aligned deposition of textile fibres in finely divided conditionupon sheet materials.

Still further objects and advantages will appear in the more detaileddescription set forth below, it being understood, however, that thismore detailed description is given by way of illustration andexplanation only and not by way of limitation, since various changestherein may be made by those skilled in the art without departing fromthe scope and spirit of the present invention.

It has been found that the above objects may be most satisfactorilyaccomplished by application of an alternating potential to the space inwhich the flock or finely divided chopped up fibres are applied to theadhesive carrying woven fabric.

A very different result is obtained by application of.

the flocking of textile 2,715,585 Patented Aug. 16, 1955 highalternating voltages than would be ordinarily ob tained by the use ofelectro-static voltage procedures involving non-varying voltages.

It has been found most satisfactory to provide two electrodes, above andbelow the fabric being flock printed, and to cause the fabric to passbetween this narrow gap Desirably the Generally a potential of between20,000 and 45,000 volts may be applied from a transformer which willstep up a normal volt or 220 volt alternating supply of 60 cycles.

Desirably the upper electrode is sieved or consists of an open grilleand is grounded, and the flock is caused to pass through such upperelectrode, after being sieved on to the upper side thereof.

The lower electrode may be connected to the step-up transformer.

Also it has been found desirable to have the upper in addition it hasbeen found most satisfactory to place a dielectric plate between thebase electrode and the fabric as it travels between the electrodes. Forexample, a glass plate of A1" thickness may be employed and this platemay cause a voltage drop thereacross of about 3,000 or 5,000 volts.

In connection with chopped up fibres there is a tendency toward atreeing and of sparking which is not normally experienced to a greatdegree with other types of finely divided particles or granulars.

To obtain satisfactory flock printing it is necessary that the voltagedrop from one electrode to the other and the movement of the electrodesin respect to one another he so controlled that this treeing andsparking will be altogether eliminated.

It is among the further objects of the present invention to provide anelectro-static flock printing procedure in which there will besubstantially no irregularities or coat the entire fabric but onlyisolated or selected areas thereof to give a predetermined flock printeddesign.

111 spite of the unevenness of the air gap due to the fact that theflock and adhesive are carried at some positions and not others on thefabric, it is important that the dielectric effects and the voltage overthe area being flock printed be maintained substantially uniform.

An important feature of the present invention resides in the fact thatthe humidity and temperature are maintained constant and that thehumidity should never exceed 40% and desirably never over 25%.

It has also been found that a fairly high concentration of ozone givesmost satisfactory qualities to the deposition and the fabric withresults.

With the foregoing and other objects in view the invention consists ofthe novel construction, combination and arrangement of parts ashereinafter more specifically described, and illustrated in theaccompanying drawings, wherein is shown an embodiment of the in vention,but it is to be understood that changes, variations and modificationscan be resorted to which fall within the scope of the claims hereuntoappended.

In the drawings wherein like reference characters denote correspondingparts throughout the several views:

Fig. l is a top schematic plan view of the flocking apparatus accordingto the present invention showing the various controls and drivers.

Fig. 2 is a vertical side sectional view upon the line 2-2 of Fig. 1upon the same scale as Fig. 1.

Fig. 3 is a side elevational view taken from the top' of Fig. 1 showingthe controls at the side of the flocking machine.

Fig. 4 is a fragmentary transverse sectional view taken upon the line4--4 of Fig. 2 showing the arrangement at the end of the flock screen,upon an enlarged scale as compared to Fig. 2.

Fig. 5 is a fragmentary transverse vertical sectional view upon the line5--5 of Fig. 2 showing the upper electrode reciprocatory drive upon anenlarged scale as compared with Fig. 2.

Fig. 6 is a top plan view of the upper electrode taken from the line 6-6of Fig. 2 and upon an enlarged scale as compared with Fig. 2.

Fig. 7 is a fragmentary vertical transverse sectional view taken uponthe line 77 of Fig. 6 to show the cross-section of the grille elementsand upon an enlarged scale as compared to Fig. 6.

Fig. 8 is a top plan view of the bottom electrode taken upon the line8-8 of Fig. 2 and upon an enlarged scale as compared to Fig. 2.

Fig. 9 is a vertical sectional view on the line 9-9 of Fig. 8 of thebottom or lower electrode.

Fig. 10 is a diagrammatic side sectional view showing the upper andlower electrodes in position with the fabric and blanket passing betweenthe same and with the flock being indicated as being applied to thefabric.

Referring to Fig. 2, there is shown a hopper A with a revolving agitatorB and at the bottom of the hopper is provided a rotating brush C.

The rotating brush delivers the flock indicated by the arrows D upon thereciprocating screen E. The screen E delivers the flock, as indicated bythe arrows F, upon the upper electrode G consisting of an open-work gridor grille. This grid or grille G is best shown in Figs. 6, 7 and 10.

Below the upper electrode or grille G is the lower electrode H, which isshown in greater detail in Figs. 8, 9 and 10.

The electrodes G and H together with the flock-feeding arrangementA-B-C-E are so enclosed in a chamber I which may be maintained at apredetermined temperature and humidity and if desired at a predeterminedair pressure.

Passing into the chamber J in the direction indicated by the arrow K isthe fabric L. This fabric L will have been previously printed with anadhesive material in an overall design or in the form of a decorativepattern.

As the fabric shown enters the chamber I, it is picked up by the blanketM, which will accompany it through the chamber.

The blanket M will pass over the glass dielectric plate N, which ispositioned above the lower electrode H.

Referring specifically to Figs. 1, 2 and 3, the chamber I has the legs 8resting on the floor 7 and supporting the bottom wall 9. The top wall 10carries the upper portion 11 of the funnel of the hopper. The chamber Ialso has the side walls 12 and the end walls 13 and 14.

The agitator B consists of two rods 15 which are connected together bythe frame elements 16 at the end thereof.

The frame members 16 are mounted upon a central shaft 17 which extendsthrough the side walls, as indicated at 18 and 19 in Fig. 1.

The shafts 17 are driven by the sprocket wheel 20 from the chain 21 (seeFig. 3).

At the bottom of the hopper A is the brush member C, which is mountedupon a shaft 22. The shaft 22 extends through the side walls 12. Theshaft 22 is driven through the sprocket wheel 23 from the chain 24.

The brush C is sufficiently wide so as to fill the opening at the bottomof the hopper A. The brush will press at 25 upon the hopper wall 26 andat 27 upon the hopper wall 28. The hopper wall 28 has a deflector or barat the short side thereof to flip the bristles of the brush B, shown inFig. 2.

The brush C will deposit the flock, as indicated by the arrows D, uponthe screen E.

The screen E is mounted at its end by the hanger 36, consisting of aflexible belt, from the bracket 37 on the top wall 10 of the chamber J.

The other end 38 of the screen E, as shown in Fig. 2, has a followermember 39, which is periodically struck by the eccentric 40.

The eccentric 41B is mounted upon the shaft 41, which also extendsthrough the side wall 12. The shaft 41 is driven by the sprocket wheel42 of the chain 43 (see Fig. 3).

As shown in Fig. 3, the sprocket wheels 20, 23 and 42 of the chaindrives 21, 24 and 43 are driven from the sprocket wheel 44. The sprocketwheel 44- is driven by the motor 45 mounted at 46 upon the top wall 10of the casing I.

From the screen E the flock will fall, as indicated by the arrows F inFig. 2, upon the upper electrode G.

The fabric L passes into the chamber I through the opening and passesout of the chamber through the opening 56.

Also passing into the chamber 1 through the opening 55 is the belt M,which will then pass out of the chamber at the opening 56.

The belt M is carried by the upper, main rollers 57 and 58 and by theadjusting, tension and guide rollers 59, 60, 61 and 62.

The roller 57 is mounted upon the shaft 63 at the front wall 13 of thechamber J.

The idler roller 62 is mounted upon the shaft 64, which is supported bythe bracket 65 at the rear wall 14 of the chamber 1. The chamber wall 14is reinforced by the channel iron 66.

On the brackets 67 are mounted the bearings 68 for the shaft 69 of theroller 58.

The transverse channel member 79 extends across the returning beltsection 71 and is supported on the springs 72. The springs 72 react onthe block 73, which is supported by the angle bracket 74 on the rearwall 14 of the chamber J. Above the belt section 71 is also the anglemember 75 on the rear wall 14.

Inside of the rear wall 14 the roller 61 is mounted upon the shaft 75.The carrier belt M then extends downwardly, as indicated at 76, to theadjusting roller 66. The adjusting roller 6% is carried on the shaft 77.

The bearings of the shaft 77 may be adjusted upwardly and downwardly bythe screw 73 connected to the manual adjusting handle 79. The screw 73passes through the head 80 having the legs 81. The legs 81 are mountedat 82 upon the bottom wall 9 of the chamber 1. By means of the adjustingscrew 78 it is possible to adjust the belt upwardly and downwardly andcontrol the tension thereon at the point 83.

The adjusting roller 59 is provided with a shaft 84, which is adjustableby means of the screw 85. The screw 35 passes through the head 86, whichis mounted by the legs 87 upon the supporting member 8 of the chamber 1.

The screw passes through the head 86 and has the adjusting wheel 88 toenabie variation of the tension upon the belt at the point 89.

The belt M will be driven together with the fabric L by the drivingroller 57.

As is shown upon Figs. 1 and 3, the shaft 63 of the roller 57 carriesthe sprocket 95, which is driven by the sprocket chain 96. The sprocketchain 96 extends up to the counter shaft 97, which carries the drivingsprocket 98, to the chain 96.

From the shaft 63 the drive extends through the sprocket chain 99 to thesprocket wheel 100 on the shaft 101 (see Fig. 3). The shaft 101 drivesthe chain 102. The chain 102 drives the sprocket wheel 103 on the shaft104. The shaft 104 carries the conveyor 105 shown in Figs. 1 and 2 andin large scale in Fig. 4.

The conveyor 105 fits in the channel 106 positioned in the end 35 of thescreen E.

The conveyor shaft 104 passes through the side wail 12 of the chamber Jto the sprocket wheel 103. The conveyor 105 will normally move theflock, as indicated by the arrow 107, to the sleeve 108. The flockpassing through the sleeve 108 will be dumped into the collector 109outside the chamber wall 12. The collector 109 consists of a back heldin position by the snap ring 110 on the collar 111. The collar 111 ismounted below the tube 108.

The cap 112 enables access to the openings 113 and The excess flockfalling 011 the screen is thus disposed of and carried to the receiver109, from which it may be re-used. The eccentric 40 will normally feedthe flock toward the screw feed 105, which will receive the balance ofthe flock which does not fall through the screen E onto the upperelectrode G.

The upper electrode G is shown in small scale in Fig. 2 and in largerscale in Figs. 5, 6, 7 and 10.

As shown in top view in Fig. 6, it consists of a grille or grid havingthe end frame members and the side frame members 121. Between the sideframe members are a plurality of oblique bars 122 which are crossed bytwo right angle bars 123. The bars 122 and 123 have a profile and crosssection, as best shown in Fig. 7, which is wedge-shaped downwardly. Theupper, narrow portions, as indicated at 124, have rounded edges 125which pass into the outwardly flared side walls 120. This will enablethe flock to flow readily downwardly, as indicated by the arrows 127.The base portions 128 of the bars 126 are widest, so as to establish abroad field and they have rounded corners 129. All corners 125 and 129are rounded to prevent any possible concentration of the electrostaticcharge and any possible breakdown of the dielectric materials withresultant sparking.

The edge frame members 120 and 121 have rounded or quarter cylindricalfaces 130 with the rounded corners 131, 132 and 133. On the sides of theplate are mounted the circular bars 134 which project, as indicated at135 and 136, from both ends of the upper electrode G. These bars arepositioned on the upper side of the electrode G and they pass betweenthe guide rollers 137 and 138.

As shown in Fig. 5, the guide rollers 137 and 138 are mounted on theside frames 139, which in turn are mounted upon the base plate 140supported on the angle irons 141.

One end of the upper electrode G is provided with the attachment 142carrying the yoke 143. The yoke 143 consists of two parallel eyes whichreceive the pivot pin 144.

The pivot pin 144 connects to the pitman 145 which extends through theopening 146 in the wall 147 and through the opening 149 in the wall 12.The pitman 145 is driven by the eccentric 150 from the shaft 151.

The shaft 151, as shown in Fig. 2, is mounted in the bearings 152 and isdriven by the bevel gear 153. The

bevel gear 153, as shown in Fig. 1, is driven by the bevel gear 154 andthe shaft 155. The shaft 155 is carried in the bearings 156 on the wall14 of the chamber I.

As a result, during the operation of the machine, the upper electrode Gwill be reciprocated laterally, as indicated by the double arrow 157,transversely of the direction of motion of the fabric L by the pitman145.

The bottom electrode H, as shown in small scale in Fig. 2 and in largescale in Figs. 8, 9 and 10, consists of a relatively flat plate with thedownturned edges 181 and the crossing bottom ribs 182 and 183.

At the crossing points 184 there are provided openings 185 for fixingand supporting the lower electrode H. The lower electrode H is desirablysupported upon the plate 186.

The plate 186 is supported by the insulation 187 mounted upon the anglemembers 189. These angle members are mounted upon the frame 190.

The electric wiring diagram is best shown in Fig. 10 and it includes onephase of an A. C. source 200 which is connected across the full windingof the variable autotransformer 201. The adjusting arm 202 of thevariable transformer is connected to one side of the resistor 203, andthe other side of the resistor is connected to one side of the primarywinding 204 of the step-up transformer 205. The other end of the primarywinding is connected by the line 206 to one side of the A. C. source.

One end of the secondary winding 207 of the step-up transformer isconnected by the line 208 to the ground 209. From the other end of thesecondary winding, the high tension line 210 may lead to the lowerelectrode H, placing an adjustable voltage with respect to groundthereon, which in the preferred form of the invention is adjusted to28,000 volts R. M. S. The upper electrode G will then be connected bythe line 211 to the ground.

If desired, the voltage may be applied to the upper electrode G and thelower electrode H to the ground. Optionally, a different type of step-uptransformer and circuit may be employed so that part of the voltage willbe applied to the upper electrode G and part to the lower electrode H,instead of applying the entire voltage of 28,000 volts (or higher orlower voltage as the case may be) to the one electrode.

The fabric L, in passing between the electrodes H and G over the glassplate N with the carrier belt M passing in the same direction, as shownin Fig. 10, will pick up the flock which flows downwardly through theinterstices 210 between the bars 122.

The flock will adhere to the 211, and will stand upright at force.

The glass plate N serves as a dielectric to reduce the possibility ofsparking or breaking down of the insulation.

The glass plate N, for example, in one instance may be one-half inchthick while the bottom electrode H is about one inch in depth.

The chamber I in a preferred form is about seven feet, six inches high,eight feet, six inches long and eightysix inches wide.

Desirably, the belt M and the wire screen E pitch slightly forwardly anddownwardly in the direction of motion of the fabric.

The upper electrode G in one embodiment of the invention may be aboutfifty-five inches in length and about thirty-eight inches in width, withthe spacing between the bars 123 being about eighteen inches and thespacing between the bars 122 being about two and onehalf inches. Thebars 120, 121, 122 and 123 may be one inch in depth and have theirgreatest width or maximum thickness of about one inch.

In operation, the high voltage will be applied with continuous sidewisereciprocation of the upper electrode G,

adhesive, as indicated at 212 under the electrostatic which willdetermine when there will be no trending and no uneven dispersal of theflock.

The oblique bars 122 and 123 will at all times pass at such an angleover the fabric L that there will be no tendency toward striping oruneven distribution of the flock.

While there has been herein described a preferred form of the invention,it should be understood that the same may be altered in details and inrelative arrangement of parts within the scope of the appended claims.

Having now particularly described and ascertained the nature of theinvention, and in what manner the same is to be performed, what isclaimed is:

1. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode, said upperelectrode consisting of a plurality of cross bars of wedge-shaped crosssection with their sides diverting downwardly and with rounded cornersand a lower electrode spaced apart, said feed carrying the material tobe flocked between the electrodes, and means to apply a high alternatingvoltage across said electrodes.

2. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode, said upperelectrode consisting of a plurality of cross bars of wedge-shaped crosssection with their sides diverting downwardly and with rounded cornersand a lower electrode spaced apart, said feed carrying the material tobe flocked between the electrodes, and means to apply a high alternatingvoltage across said electrodes, said feed including a belt passingcontinuously between said upper and lower electrodes.

3. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode, said upperelectrode consisting of a plurality of cross bars of wedge-shaped crosssection with their sides diverting downwardly and with rounded cornersand a lower electrode spaced apart, said feed carrying the material tobe flocked between the electrodes, and means to apply a high alternatingvoltage across said electrodes, said high voltage being applied to oneelectrode and the other electrode being grounded.

4. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode, said upperelectrode consisting of a plurality of cross bars of wedge-shaped crosssection with their sides diverting downwardly and with rounded cornersand a lower electrode spaced apart, said feed carrying the material tobe flocked between the electrodes, and means to apply a high alternatingvoltage across said electrodes, one of said electrodes being providedwith means to laterally reciprocate the same transversely of thematerial to be flocked.

5. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode, said upperelectrode consisting of a plurality of cross bars of wedge-shaped crosssection with their sides diverting downwardly and with rounded cornersand a lower electrode spaced apart, said feed carrying the material tobe flocked between the electrodes, and means to apply a high alternatingvoltage across said electrodes, said upper electrode consisting of alattice-work having a plurality of bars extending obliquely to thedirection of feed of the material to be flocked.

6. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode, said upperelectrode consisting of a plurality of cross bars of wedge-shaped crosssection with their sides diverting downwardly and with rounded cornersand a lower electrode spaced apart, said feed carrying the material tobe flocked between the electrodes, and means to apply a high alternatingvoltage across said electrodes, and a glass plate positioned above saidlower electrode between the material to be flocked and the feed for thematerial to be flocked.

7. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode, said upperelectrode consisting of a plurality of cross bars of wedge-shaped crosssection with their sides diverting downwardly and with rounded cornersand a lower electrode spaced apart, said feed carrying the material tobe flocked between the electrodes, and means to apply a high alternatingvoltage across said electrodes, and an enclosure for said upper andlower electrodes to enable a constant moisture content and humidity tobe maintained adjacent to said electrodes.

8. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode and a lowerelectrode spaced apart, said feed carrying the material to be flockedbetween the electrodes, and means to apply a high alternating voltageacross said electrodes, said upper electrode consisting of a latticeworkhaving bars of trapezoidal cross section which are widest at theirbottom edges and said lower electrode consisting of a solid plate, theupper electrode being grounded and the lower electrode being connectedto the alternating voltage source.

9. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode and a lowerelectrode spaced apart, said feed carrying the material to be flockedbetween the electrodes, and means to apply a high alternating voltageacross said electrodes, said high voltage being applied to bothelectrodes and a reciprocating screen positioned above said upperelectrode and below the flock delivering means, said screen beinguncharged.

10. A method of flock printing fabrics which comprises passing a fabricwhile depositing flock thereon between two metal plates, said platesbeing arranged one above the other and the upper plate being an opengrille-work both of which metal plates are subjected to a highalternating voltage, said fabric and metal plates being positionedhorizontally and said metal plates serving as high potential staticcharge electrodes and said flock being screened above said upperelectrode and being caused to pass through the interstices of said upperelectrode onto said fabric.

11. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode and a lowerelectrode spaced apart, said feed carrying the material to be flockedbetween the electrodes, and means to apply a high alternating voltageacross said electrodes, one of said electrodes being provided with meansto reciprocate the same longitudinally of the material to be flocked anda reciprocating screen positioned above said upper electrode and belowthe flock delivering means, said screen being uncharged.

12. A flock printing machine comprising a feed for the material to beflocked, a feed for the flock, an upper electrode and a lower electrodespaced apart, said feed carrying the material to be flocked between theelectrodes, and means to apply a high alternating voltage across saidelectrodes, said upper electrode consisting of a latticework having aplurality of bars extending transversely obliquely to the direction offeed of the material to be flocked and a reciprocating screen positionedabove said upper electrode and below the flock delivering means, saidscreen being uncharged.

13. A flock printing machine comprising a feed for the material to beflocked, a feed for the flock, an upper electrode and a lower electrodespaced apart, said feed carrying the material to be flocked between theelectrodes, and means to apply a high alternating voltage across saidelectrodes, said upper electrode consisting of a lattice-work having aplurality of spaced parallel wedge-shaped bars extending obliquely tothe direction of feed of the material to be flocked and a reciprocatingscreen positioned above said upper electrode and below the flockdelivering means, said screen being uncharged.

14. A flock printing machine comprising a feed for the material to beflocked, a feed for the flock, an upper electrode and a lower electrodespaced apart, said feed carrying the material to be flocked between theelectrodes, and means to apply a high alternating voltage across saidelectrodes, said upper electrode consisting of a latticework having barsof trapezoidal cross section which are widest at their bottom edges andsaid lower electrode consisting of a solid plate, the lower electrodebeing connected to a source of a high alternating current voltage andthe upper electrode being grounded and a reciprocating screen positionedabove said upper electrode and below the flock delivering means, saidscreen being uncharged.

15. A flock printing machine comprising a feed for the material to beflocked, flock delivering means, an upper electrode and a lowerelectrode spaced apart, said feed carrying the material to be flockedbetween the electrodes, and means to apply a high alternating voltageacross said electrodes, said upper electrode consisting of a latticeworkhaving bars of trapezoidal cross section which are widest at theirbottom edges and said lower electrode consisting of a solid plate, thealternating current voltage applied across the upper and lowerelectrodes with the upper electrode being grounded and a reciprocatingscreen positioned above said upper electrode and below the flockdelivering means, said screen being uncharged.

16. A flock deposition electrode system comprising an upper metal grilleplate serving as an upper electrode, a lower metal plate parallel tosaid grille plate and serving as a lower electrode, intervening rubberand glass plates, the material to receive the flock being positionedbetween the upper metal electrode and the lower rubber and glass plateswhich are positioned above the lower electrode.

17. The system of claim 16 in which the grille plate is provided withreciprocatory means.

18. The system of claim 16 in which the upper metal grille plate isprovided with a series of obliquely arranged transverse bars forming anopen grille plate.

19. An electrostatic flocking apparatus comprising an upper oblique-bargrille reciprocating electrode, a lower solid plate fixed electrode, atransformer the output ends of which are connected respectively to theupper and lower electrodes, an upper reciprocating screen to screen theflock onto the upper electrode and a fabric carrier to pass between theupper and lower electrodes.

20. The apparatus of claim 19, said grille being formed of bars whichare divergent downwardly.

21. The apparatus of claim 19, a fixed glass plate being positionedbetween the fabric carrier and the lower electrode.

22. The apparatus of claim 19, said upper electrode being provided withmeans to reciprocate said electrode laterally of the direction ofmovement of the fabric carrier.

23. The apparatus of claim 19, said upper grille being provided withside supporting and guiding bars and guide rollers to guide said bars toassure lateral reciprocation of said grille electrode.

24. A process of electrostatically depositing flock upon a fabric whichhas been printed with adhesive in a flocking apparatus which comprisesan upper uncharged reciprocating screen, an intermediate lowergrille-like open electrode, said screen, glass plate and metalelectrodes being all positioned horizontally and parallel to each other,the step which comprises passing the fabric to be flocked horizontallybetween the glass plate and the open electrode whilst causing screenflock to flow through the openings in the grille-like open electrodeonto the fabric and simultaneously applying a high reciprocating staticcharge of the order of between 20,000 to 45,000 volts to the electrodes.

25. The process of claim 24 is of quarter inch thickness and across of3000 to 5000 volts.

26. A method of flock printing fabrics which comprises passing a fabricwhile depositing flock thereon between two metal plates, said metalplates having an intervening glass plate, one of which metal plates isgrounded and the other of which metal plates is subjected to highalternating voltage, said plates being arranged one above the other andthe upper plate being an open grille-work, said fabric and metal platesbeing positioned horizontally and said metal plates serving as highpotential static charge electrodes and said flock being screened abovesaid upper electrode and being caused to pass through the interstices ofsaid upper electrode onto said fabric.

in which the glass plate has a voltage drop there- References Cited inthe file of this patent UNITED STATES PATENTS 2,173,032 Wintermute Sept.12, 1939 2,187,624 Melton et al J an. 16, 1940 2,356,489 Amstuz Aug. 22,1944

10. A METHOD OF FLOCK PRINTING FABRICS WHICH COMPRISES PASSING A FABRICWHILE DEPOSITING FLOCK THEREON BETWEEN TWO MATAL PLATES, SAID PLATESBEING ARRANGED ON ABOVE THE OTHER AND THE UPPER PLATE BEING AN OPENGRILLE-WORK BOTH OF WHICH METAL PLATES ARE SUBJECTED TO A HIGHALTERNATING VOLTAGE, SAID FABRIC AND METAL PLATES SERVING AS HIGH TIONEDHORIZONTALLY AND SAID METAL PLATES SERVING AS HIGH POTENTIAL STATICCHARGE ELECTRODES AND SAID FLOCK BEING SCREEND ABOVE SAID UPPERELECTRODE AND BEING CAUSED TO PASS THROUGH THE INTERSTICES OF SAID UPPERELECTRODE ONTO SAID FABRIC.